Writing exercise/block killer

"you can't just leave me like this"
The tears flowed freely. His chin did that stupid quivery thing- the one that almost melted her. He hated it: hated displaying such weakness, such...humanity.
Sure he was the first to admit, even point out, his shortcomings but this was completely different. He sank to the floor awash in loss. Pleading, begging, he cast eyes toward her.
I haven't done anything wrong. Thought or spoken? Unknown.
Words escaped her lips, those perfect lips, swollen and flush with emotion. She spoke with forced composure but aside from her tics and the quavering in her voice he did not pick up meaning in it. God, those lips. His mind leapt to the last time they'd...no. That was inappropriate right now. Wasn't it?
Her hand brushed his arm. He reflexively closed his eyes, took the moment in. Her touch awakened him momentarily and he almost smiled.
They were driving now. It was summer. With the windows open her hair blew into her face. She brushed it away, somehow both absentminded and irritatedly.
"where are you right now?" she asked. "What were you just thinking?"
"nothing"
..nothing at all.
He was thinking stupid things again, crazy things. Lately mortality rocked his psyche. Death was at every turn just waiting to ambush him. Each ache, every pain was malignant. Everyone was out to get him. So he got lost often, trapped by his bleeding insecurity.
As he sat there slowly dying she began a germination...well, two really - but that's neither here nor there yet. She looked at this boy she was sure she'd loved and began to find him unattractive, appalling, even. Every subtle sigh the world elicited from him irked her. Life wasn't that bad, really. Not all that bad at all. She was young and attractive, vibrant, and never suffered for it.
The seed sprouted and roots took hold. Her repulsion became evident to all around but him. When he'd rest a loving hand on her thigh, or would whisper to her how beautiful she looked she had to fight back the urge to gag. Occasionally she would visibly cringe. Everyone noticed. Nothing was said.

The two lovers lay together clenched in sleeps sweet embrace. He abruptly shook and let out a cry. The cry woke, and chilled, her. It was primal, terrifying, childlike. She sat up and squeezed his hand but he slept, unaware his trespass.

She knew then she had to leave him.

In the morning he woke to a freezing room. He body wasn't warming him. He flopped onto his back and pulled an arm over his face, lost for a moment of private doom. He sat up, dizzy, feeling exhausted. He rubbed his eyes reflexively as he shuffled to their coffeemaker, poured himself a cup, and found her on the patio smoking. She looked as tired as he felt.
"how long have you been up?"
"few hours"
They sat, shriveled, insomniac. He knew something was off. He wanted desperately to make her laugh - to flash that smile that fueled his failing world, but couldn't muster the positivity required. They conversed as old couples do; mostly familiar noises and subdued acknowledgments. She stared past him. He tried to locate the core of her via those sleepy portals. Failing that, he tried to pour his all into his. He needed her to see and understand. He pushed her his world, the unexplainable sorrow, the terror, the insurmountable loss that was existence. More importantly, he pushed the warmth that was his love for her. That warmth, his shining beacon in a world of pitch. Please understand this he thought, desperate. please understand me
She sat upright abruptly, eyes finally focusing in on him.
"have sex with me."